Curable emulsions, in which an oil phase containing a curable material is dispersed in an aqueous phase, are widely used in the manufacture of articles that include a binder material.
A common problem of curable emulsions is their tendency to settle out over time, which may cause handling problems and/or reduce shelf life of the curable emulsion. One approach to addressing the settling issue involves the addition of a relatively large quantity (e.g., approximately 10 percent by weight or more) of emulsifier to the oil phase. Although this approach may provide some relief from settling, on drying and curing the emulsion, the presence of a high amount of emulsifier typically degrades one or more properties (e.g., reduced tensile strength and/or elongation at break) of the resultant cured material (i.e., a material that is polymerized and/or crosslinked to a degree sufficient to impart useful physical properties).
Polyurethanes (i.e., polymers containing urethane and/or urea linkages in the backbone chain) are widely used as binder materials for many applications due to their physical properties (e.g., strength, elongation, and/or toughness).
It would be desirable to have curable emulsions containing materials that are stable for a long time, and that may be dried and cured to provide polyurethanes with good physical properties.